The kidney serves as a target organ for insulin and glucagon; these hormones affect the renal handling of sodium and potassium. The kidney also indirectly determines the effects of these hormones on the organism as a whole by virtue of its importance as a significant site of insulin degradation and glucagon degradation. At the cellular level, studies of interaction between these hormones and kidney have been extremely limited. This paucity of data is largely due to technical and interpretive difficulties when using kidney slices or kidney tubule preparations. The proposed experiments are designed to eliminate these problems through the preparation and use of isolated cells of a single cell type. The availability of homogeneous populations of a specific cell type will permit comparative studies of 1) insulin binding and glucagon binding kinetics, 2) cell specific cleavage of these hormones, and 3) insulin action and glucagon action on renal cortical cells.